Power distribution unit system incorporating smart cables and adapters

ABSTRACT

An adapter for interconnecting a power distribution unit (PDU) to electrical equipment. The adapter can include a first connector mateable with an outlet of the PDU and a second connector in electrical communication with the first connector. The second connector is mateable with a power input of the electrical equipment. PDU interface circuitry incorporating an optical interface can be housed in the first connector for communicating one or more electrical parameters of the electrical equipment to the PDU when the first connector is mated with the outlet of the PDU.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a division of U.S. patent application Ser. No.15/497,063, entitled “Power Distribution Unit System Incorporating SmartCables and Adapters,” filed Apr. 25, 2017, which is acontinuation-in-part of U.S. patent application Ser. No. 15/169,940,entitled “Power Distribution Unit with Cord Storage Cartridge,” filedJun. 1, 2016, the disclosures of which are hereby incorporated byreference in their entirety.

TECHNICAL FIELD

The present disclosure is directed to power distribution devices and,more specifically, to power distribution unit systems capable ofproviding a high density of outlets that are adaptable to varying plugtypes and providing modular intelligence for outlet monitoring andswitching.

BACKGROUND

A conventional Power Distribution Unit (PDU) is an assembly ofelectrical outlets (also called receptacles) that receive electricalpower from a source and distribute the electrical power to one or moreseparate pieces of electronic equipment having respective power cordsplugged into respective outlets of the PDU. PDUs are used in manyapplications and settings such as, for example, in or on electronicequipment racks. One or more PDUs are commonly located in an equipmentrack (or other cabinet), and may be installed together with otherdevices connected to the PDU such as environmental monitors, temperatureand humidity sensors, fuse modules, or communications modules that maybe external to or contained within the PDU housing. A PDU that ismountable in an equipment rack or cabinet may sometimes be referred toas a Cabinet PDU or CDU for short.

A common use of PDUs is supplying operating power for electricalequipment in computing facilities, such as enterprise data centers,multi-tenant hosting environments like colocation facilities, cloudcomputing, and other data center types. Such computing facilities mayinclude electronic equipment racks that comprise rectangular orbox-shaped housings, sometimes referred to as a cabinet or a rack, andassociated components for mounting equipment, associated communicationscables, and associated power distribution cables. Electronic equipmentmay be mounted in such racks so that the various electronic devices(e.g., network switches, routers, servers and the like) are alignedvertically, one on top of the other, in the rack. Multiple PDUs may beused to provide power to the electronic equipment where redundantconfigurations are required. Multiple racks may be orientedside-by-side, with each containing numerous electronic components andhaving substantial quantities of associated component wiring locatedboth within and outside of the area occupied by the racks.

As will be readily recognized, space within equipment racks is valuable,with maximization of computing resources for any given volume beingdesirable. Therefore, it is desirable to ensure that the componentswithin the equipment rack have maximum up-time. To accomplish this, manycomponents include redundant power supplies connected to redundant PDUsin order to reduce the possibility that equipment will go down due tolack of power. Redundant PDUs require twice the number of power cablesas compared to single PDU configurations. Accordingly, management of theassociated power distribution cables can become problematic.

SUMMARY

The evolution of computing equipment is toward higher electricalefficiency and smaller volume, resulting in higher densities ofcomputing equipment within a rack that requires at least an equivalentnumber of power outputs. For this reason, a PDU that provides thenecessary number of power outputs while also reducing the area occupiedby the PDU housing and associated power distribution cables iscommercially advantageous. Furthermore, a PDU that allows for theshortest cables and the least number of different cable lengths canprovide additional advantages over conventional PDUs. For example,shorter cables can facilitate increased cooling air flow to thecomponents in a rack and simplifies the replacement of cables and thecomponents themselves. In addition, reducing the number of differentlengths of cables can simplify purchasing and management of differentpower cables for an enterprise.

Apparatuses, devices, systems, and methods are provided in the presentdisclosure that maximizes the number of power outputs (e.g., outletconnectors) available on a PDU, while also providing for flexibility inconnecting to different plug types and minimizing cord lengths and thenumber of different cord lengths. Different pieces of equipment may havedifferent power needs requiring different power cords having differentplugs to support different power ampacities. In some aspects, a PDUaccording to a representative embodiment includes an elongate PDUhousing having opposed front and rear panels with a plurality of sidepanels extending therebetween. The front panel can have a width betweenabout 1.7 inches and about 3.0 inches. In some embodiments, the frontpanel includes an outlet region extending along a length of the PDU anda non-outlet region positioned side-by-side with the outlet region. Insome embodiments, the outlet region can have a width less than about0.83 inches. A plurality of outlet cores are arranged along the lengthof the outlet region of the front panel, wherein the outlet regionincludes a plurality of apertures each corresponding to an associatedone of the plurality of outlet cores.

In another representative embodiment, a PDU includes an elongate housinghaving an outlet panel extending along a length of the PDU and anon-outlet panel parallel to and offset from the outlet panel. A powerinput is coupled with the PDU housing and is connectable to an externalpower source. One or more PCBs can be mounted within the housing andelectrically interconnected to the power input. A plurality of outletcores are arranged along the outlet panel preferably with 1 U spacingand mounted to the one or more PCBs with an unobstructed space betweenadjacent pairs of the plurality of outlet cores. In some embodiments,the outlet cores each extend a portion of the distance between the oneor more PCBs and the outlet panel. The outlet panel can include aplurality of apertures each corresponding to an associated one or moreof the plurality of outlet cores. In some embodiments, one or morecircuit protection devices, such as circuit breakers are, mounted in thenon-outlet panel and aligned along the length of the housing.

In some aspects, a smart cable for removable attachment to a PDU,according to a representative embodiment, includes a connector housingconfigured to removably connect the smart cable to a mateable interfaceof a PDU. A power output cable extends into the connector housing at oneend and couples to an output connector at the opposite end. A PDUinterface is disposed in the connector housing and can include a uniqueidentifier encoded in a memory device, a sensing device configured tosense at least one power-related parameter of the power output cable,and an optical signal interface. The optical signal interface isconfigured to report the at least one power-related parameter and theunique identifier to the PDU. In some embodiments, smart cables caninclude additional sensors, for example and without limitation,temperature sensors, differential pressure sensors, humidity sensors,air flow sensors, water detection sensors, and electrical (on/off)switches, which can be used to detect access into computer equipmentracks. In some embodiments, indicia corresponding to the uniqueidentifier is attached to the power output cable. In some embodiments,the PDU interface is configured to read a unique identifier stored on anidentifier tag, for example.

In some aspects, a power connector adapter, according to arepresentative embodiment, includes a first connector configured to matewith an industry standard connector (e.g., IEC C2, C4, C6, C8, C10, C12,C14, C16, C16A, C18, C20, C22, C24 or NEMA 5-15R, 6-20R, 6-30R, 6-50R)and a second connector configured to mate with a non-industry standardconnector. In various embodiments, industry standard connectors caninclude connectors defined in International Electro technical Commission(IEC) standard publication IEC60320 as of the filing date of the presentapplication. In some embodiments, the non-industry standard connectorincludes at least three aligned terminals. A plurality of electricalconductors extend between the first connector and the second connector.In some embodiments, a first attachment mechanism is associated with thefirst connector and a second attachment mechanism is associated with thesecond connector. The second attachment mechanism can be movable from asecured state, in which said attachment mechanism can retainably couplethe power connector adapter to a PDU, to an unsecured state to allowremoval of the power connector adapter from the PDU.

The foregoing broadly outlines the features and technical advantages ofexamples according to the disclosure in order that the detaileddescription that follows may be better understood. Additional featuresand advantages will be described hereinafter. The concepts and specificexamples disclosed herein may be readily used as a basis for modifyingor designing other structures for carrying out the same purposes of thepresent disclosure. Such equivalent constructions do not depart from thespirit and scope of the appended claims. Features which are believed tobe characteristic of the concepts disclosed herein, both as to theirorganization and method of operation, together with associatedadvantages will be better understood from the following description whenconsidered in connection with the accompanying figures. Each of thefigures is provided for the purpose of illustration and descriptiononly, and not as a definition of the limits of the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

A further understanding of the nature and advantages of the presenttechnology may be realized by reference to the following drawings. Inthe appended figures, similar components or features may have the samereference label.

FIG. 1A is an isometric view of a conventional equipment rack system;

FIG. 1B is a rear view in elevation of the conventional equipment racksystem shown in FIG. 1A;

FIG. 1C is an isometric view of a conventional equipment rack system;

FIG. 1D is an isometric view of another conventional equipment racksystem having two PDUs positioned side by side;

FIG. 2A is an isometric view of a representative embodiment of anequipment rack system that includes two PDUs in accordance with variousaspects of the present disclosure;

FIG. 2B is a rear view in elevation of the equipment rack system shownin FIG. 2A;

FIG. 3A is an enlarged partial isometric view of a smart cable andconnector adapters, each according to a representative embodiment;

FIG. 3B is an enlarged partial isometric view showing a smart cableconnected to an electronic appliance, such as a server;

FIG. 4A is an isometric view of a representative one of the PDUsintroduced in FIGS. 2A and 2B;

FIG. 4B is an isometric view of a two-piece PDU according to arepresentative embodiment having horizontal and vertical components;

FIG. 5 is a top plan view of the PDU shown in FIG. 4A;

FIG. 6 is an enlarged view of a portion of the PDU as shown in FIG. 5;

FIG. 7 is a side view in elevation of the PDU shown in FIGS. 4A, 5, and6;

FIG. 8 is a partial cross-sectional view of the PDU taken about line 8-8in FIG. 7 for illustrating some of the structural components therein;

FIG. 9 is a partial isometric view of the PDU illustrating indiciaaccording to a representative embodiment;

FIG. 10 is an isometric view illustrating an outlet connector accordingto a representative embodiment;

FIG. 11 is an exploded isometric view illustrating the outlet connectorshown in FIG. 10;

FIG. 12 is an isometric view illustrating a connector adapter accordingto a representative embodiment;

FIG. 13 is an isometric view illustrating a connector adapter accordingto another representative embodiment;

FIG. 14 is an isometric view illustrating the connector adapter shown inFIG. 13 as viewed from the opposite end;

FIG. 15 is an isometric view illustrating the internal components of theconnector adapter of FIG. 12;

FIG. 16 is an isometric view illustrating a connector adapter coveraccording to a representative embodiment;

FIG. 17A is an isometric view illustrating a smart cable according to arepresentative embodiment;

FIG. 17B is an isometric view illustrating a portion of a smart cableaccording to another representative embodiment;

FIG. 18 is an isometric view illustrating the internal components of thesmart cable connector of FIG. 17A;

FIG. 19 is a circuit diagram illustrating an example of a power supplycircuit, in accordance with various aspects of the present disclosure;

FIG. 20 is a circuit diagram illustrating an example of an opticalcommunication circuit, in accordance with various aspects of the presentdisclosure;

FIG. 21A is a circuit diagram illustrating an example of a currentmeasurement circuit, in accordance with various aspects of the presentdisclosure;

FIG. 21B is a circuit diagram illustrating an example of a controlcircuit, in accordance with various aspects of the present disclosure;

FIG. 22 is a circuit diagram illustrating an example of a voltageconvertor circuit, in accordance with various aspects of the presentdisclosure;

FIG. 23 is a circuit diagram illustrating an example of a PDUcommunication interface, in accordance with various aspects of thepresent disclosure;

FIGS. 24A-24D diagrammatically illustrate various representativeembodiments of power connector adapters which are contemplated by thepresent disclosure;

FIGS. 25A-25H diagrammatically illustrate various representativeembodiments of smart cables and smart power connector adapterscontemplated by the present disclosure;

FIG. 26 is an exploded isometric view illustrating a cableidentification system according to a representative embodiment;

FIG. 27 is an end view of the PDU connector shown in FIG. 26;

FIG. 28 is a side view in elevation of the cable identification systemwith the PDU connector connected to the outlet; and

FIG. 29 is a cross-sectional view of the cable identification system astaken about line 29-29 in FIG. 28.

DETAILED DESCRIPTION

Systems, methods and devices are provided that allow for efficient andflexible distribution of power to equipment located, for example, in anelectrical equipment rack. Aspects of the present disclosure providePDUs with the necessary number of power outputs while also reducing thevolume occupied by the PDU housing and associated power distributioncables. Furthermore, the disclosed PDU configurations allow for theshortest cables and the least number of different cable lengthsproviding additional advantages over conventional PDUs. Aspects of thepresent disclosure also provide power connector adapters for connectingindustry standard connectors of electrical equipment with non-industrystandard connectors of the disclosed PDUs. Other aspects of the presentdisclosure further provide smart cables for connecting electricalequipment to the disclosed PDUs. In some embodiments, the smart cablesare configured to provide various capabilities such as outlet switching,report power-related information about the electrical equipment, andread and/or store a unique identifier and report the identifier to thePDU. The unique identifier can be used to track the electricalequipment.

The disclosed power distribution unit system incorporating smart cablesand adapters includes a basic PDU and configurable smart cables that canbe connected to the PDU and equipment as needed. Each smart cable can beconfigured as needed with various features, such as switching, metering,and asset tracking, for example. Accordingly, only one or a limitednumber of PDU variations (e.g., different numbers of outlets) need bestocked in inventory to satisfy most if not all customer configurationdemands. Similarly, only one or a few smart cable variations (e.g.,different connectors) need be stocked in order to meet variousconfiguration demands. Thus, manufacturing costs can be reduced due toeconomies of scale and reduced inventory requirements. Similarly, thecustomer can reduce the number of items they are required to keep onhand for replacements.

The smart cable can be easily reconfigured and/or upgraded with softwarechanges when equipment is upgraded, replaced, or when applicationconfigurations change. The disclosed connector adapters furtherfacilitate adapting to configuration changes where connector types(e.g., C13 or C19) change. The disclosed power distribution unit systemincorporating smart cables and adapters can also improve serviceability.If a smart cable fails, only that cable need be replaced, rather thanthe entire PDU as is the case with conventional PDU configurations.Replacing only the smart cable is more cost effective and less timeconsuming as well. Because most of the circuitry is in the smart cable,the PDU is less likely to fail and if it does it is less expensive toreplace than a full featured PDU.

This description provides examples, and is not intended to unnecessarilylimit the scope, applicability, or configuration of the inventionsherein. Rather, the ensuing description will provide those skilled inthe art with an enabling description for implementing embodiments of theinventions. Various changes may be made in the function and arrangementof elements. Thus, various embodiments may omit, substitute, or addvarious procedures or components as appropriate. For instance, aspectsand elements described with respect to certain embodiments may becombined in various other embodiments. It should also be appreciatedthat the following systems, devices, and components may individually orcollectively be components of a larger system, wherein other proceduresmay take precedence over or otherwise modify their application.

The following patents and patent applications are incorporated herein byreference in their entirety: U.S. Pat. No. 7,043,543, entitled“Vertical-Mount Electrical Power Distribution Plugstrip,” issued on May9, 2006; U.S. Pat. No. 7,990,689, entitled “Power Distribution Unit AndMethods Of Making And Use Including Modular Construction AndAssemblies,” issued on Aug. 2, 2011; U.S. Pat. No. 8,494,661, entitled“Power Distribution, Management, and Monitoring Systems,” and issued onJul. 23, 2013; U.S. Pat. No. 8,321,163, entitled “MonitoringPower-Related Parameters in a Power Distribution Unit,” and issued onNov. 27, 2012; U.S. Pat. No. 8,541,906, entitled “Polyphase PowerDistribution and Monitoring Apparatus,” and issued on Sep. 24, 2013;U.S. Pat. No. 8,305,737, entitled “Power Distribution Apparatus WithInput and Output Power Sensing and Method of Use,” and issued on Nov. 6,2012; U.S. Pat. No. 8,587,950, entitled “Method and Apparatus forMultiple Input Power Distribution to Adjacent Outputs,” and issued onNov. 19, 2013; and U.S. application Ser. No. 14/959,207, entitled“Magneto-Resistive Sensor Device and Magnetic Bias Regulator Circuit,Along With Systems And Methods Incorporating Same,” and filed on Dec. 4,2015.

FIGS. 1A and 1B illustrate a conventional equipment rack system 10. Theequipment rack system 10 includes an equipment cabinet 12 and electronicequipment 20 mounted in the equipment cabinet 12. The electronicequipment 20 may include various electronic devices, such as networkswitches, routers, servers and the like. A conventional PDU 14 is alsomounted within the equipment cabinet 12. The conventional PDU 14 has apredetermined number of outlets of a certain type, which are spaced atpredetermined intervals along the PDU 14. FIGS. 1A and 1B illustratePDUs having 30 outlets, but PDUs can have any suitable number of outletsof various types. Separate power cords 16 connect the outlets of the PDU14 to the electronic equipment 20. Many specific lengths of power cords16 need to be used to keep the power cords 16 organized and to maintainproper airflow around the equipment cabinet 12.

When changing or removing electronic equipment 20 from the equipmentcabinet 12, the corresponding power cords 16 need to be located andunplugged. Due to the bundling of the power cords 16, locating andremoving the necessary cords may be time-consuming and difficult.Furthermore, when adding electronic equipment 20 to the equipmentcabinet 12, the conventional PDU 14 may not have available outlets nearthe location of the electronic equipment 20. In these cases, longerpower cords 16 may need to be used to connect the electronic equipment20 to the available outlets. These longer power cords 16 may cause theelectronic equipment 20 to be more difficult to access and may impactthe airflow around the equipment cabinet 12. The conventional PDU 14 mayalso not have outlets of the correct type for connecting differentelectronic equipment 20. In these cases, an outlet adapter or adifferent PDU may be necessary in order to connect the electronicequipment 20.

FIG. 1C illustrates another conventional equipment rack system 30 havinga conventional PDU 15 and electronic equipment 20 positioned in anequipment cabinet 13. Power cords 17 connect the power supplies 22 tothe PDU 15. FIG. 1D illustrates a conventional equipment rack system 32having two conventional PDUs 15(1) and 15(2) (PDUs 15 collectively)positioned side by side in an equipment cabinet 13. The equipment racksystem 32 includes electronic equipment 20 mounted in the equipmentcabinet 13. Each piece of electronic equipment 20 can include tworedundant power supplies 22, each of which is connected to one of thetwo PDUs 15. Separate power cords 17 connect the power supplies to thePDUs 15. As with the conventional equipment rack system 10 describedabove with respect to FIGS. 1A and 1B, when changing or removingelectronic equipment 20 from the equipment cabinet 13, the correspondingpower cords 17 need to be located and unplugged, which may betime-consuming and difficult. However, in this case the process isfurther complicated by having two PDUs.

FIGS. 2A and 2B illustrate an embodiment of an equipment rack system 100that includes a pair of PDUs 110 each configured in accordance with anembodiment of the present technology. The PDUs 110 overcome the problemsof the conventional PDU 14 described in reference to FIGS. 1A and 1B,and also provides additional benefits, as further described herein. Theequipment rack system 100 includes an equipment cabinet 12 andelectronic equipment 20 mounted in the equipment cabinet 12. Theelectronic equipment 20 may include various electronic devices, such asnetwork switches, routers, servers and the like. The PDUs 110 are alsomounted within the equipment cabinet 12. As explained more fully below,each PDU 110 includes a plurality of outlet connectors 160 configured toallow a spacing of one rack unit (1 U) between outlets. In addition, theoutlet connectors 160 allow the PDU 110 to have a width narrower thanconventional PDU designs. This is due, at least in part, to theirnarrower form factor and orientation within the PDU 110. In certainimplementations a customer might need to place PDUs on both sides of therack due to space limitations within the rack. The disclosed PDUs withtheir approximate 1 U spacing allow that customer to place two PDUs onthe same side of the rack. The combination of 1 U outlet spacing withside-by-side PDU mounting is not available with conventional PDUdesigns. The narrower widths of the PDUs 110 also allow two PDUs to bemounted side by side in a shallower equipment cabinet than that requiredwith conventional PDUs, such as those illustrated in FIG. 1D.Furthermore, the narrower widths of the PDUs 110 allow two PDUs to bemounted side by side in an equipment cabinet using industry standardmounting features (e.g., keyhole mounting apertures) typically spacedapproximately 2.2 inches apart.

As can be appreciated in FIGS. 2A and 2B, only two different lengthpower cords 112 and 114 are needed to connect all of the electronicequipment's power supplies 22 to the PDUs 110. Furthermore, because twooutlets are available at each rack unit location, the power cords 112and 114 can extend straight across (i.e., horizontally) from each powersupply 22 to a corresponding outlet on one of the PDUs 110. In someembodiments, the power cords 112 and 114 can include industry standardconnectors such as any of various IEC type connectors (e.g., IEC C13/C14or IEC C19/C20). Appropriate power cords can be connected at one end tothe electronic equipment 20 and connected at the other end to acorresponding PDU 110 via a power connector adapter, for example. Itshould be appreciated that the PDUs depicted in FIG. 2A each have 42receptacles while the conventional PDU shown in FIG. 1C has only 24receptacles. A conventional PDU having 42 receptacles would need to beconsiderably wider (if the length remains fixed) in order to supportthis number of outlets. It should be understood that the electronicequipment depicted in the figures is intended to be a representation ofsuch equipment and that variations to the appearance and layout of theequipment's features can vary. For example, the power supplies could beon one side or the other of the equipment.

As shown in FIG. 3A, power connector adapters 116 and 118 are configuredin accordance with embodiments of the present technology to adapt IECC13/C14 and IEC C19/C20 power cords, respectively, to the outletconnectors 160 of the PDUs 110. In the embodiments of FIG. 3A, the powerconnector adapters 116 and 118 are illustrated as including IEC-typeconnectors, although it will be readily understood that any of variousother types of connectors can be used. For example and withoutlimitation, the power connector adapters 116 and 118 can include NEMAtype connectors (e.g., NEMA 5-15R, NEMA 6-20R, NEMA 6-30R or NEMA 6-50R)or any other of the various IEC type connectors.

In some embodiments, a smart cable 120 can be used to connect electronicequipment to the PDUs 110. As explained more fully below, the smartcable 120 can supply power from the PDU 110 to the electrical equipmentand can be configured to report power-related information and/orparameters about the electrical equipment, as well as a uniqueidentifier corresponding to the electrical equipment, to the PDU 110. Insome embodiments, the smart cable 120 includes a PDU connector 124configured to mate with the PDU 110 and to house a PDU interface forreporting the power-related information and the unique identifier aswell as provide power switching. In other embodiments, such as shown inFIG. 3B, a smart cable 122 includes a connector 126 configured to matewith the electronic equipment (e.g., industry standard connector) andhouse the PDU interface, rather than the PDU interface being housed inthe PDU connector.

Turning to FIG. 4A, the PDU 110 includes an elongate PDU housing 130including a front face having an outlet panel 132 extending along alength of the PDU 110 and a non-outlet panel 134 parallel to and offsetfrom the outlet panel 132. Accordingly, the front of the PDU 110includes an outlet region extending along a length of the PDU and anon-outlet region positioned side-by-side with the outlet region. Thehousing 130 includes a rear face having a rear panel 136 positionedopposite the outlet panel 132 and the non-outlet panel 134 with a pairof sidewalls 138 and 140 extending therebetween. An intermediate panel135 extends orthogonally between the outlet panel 132 and the non-outletpanel 134 such that the non-outlet panel 134 is raised relative to theoutlet panel 132. The housing 130 also includes an end wall 142 and anendcap 144 positioned opposite the end wall 142.

The endcap 144 includes a cord opening 146 configured to receive a powerinput cord (not shown) that penetrates the PDU housing 130. The powerinput cord may be connected to an external power source to provide powerto the PDU 110. In some embodiments, the external power source mayprovide multiple phases of power, from a polyphase power source, to thePDU 110. The power input cord electrically interconnects one or morepower line circuits (not shown) of the PDU 110 to the external powersource. Each of the power line circuits may be associated with a phaseof power provided by the external power source.

In some embodiments, the non-outlet region or non-outlet panel 134supports various non-outlet components, such as overcurrent protectiondevices 150, a power metrics display 152, and a communications interface154, for example. In some embodiments, the components can be alignedalong the length of the housing as shown in the depicted embodiment. Theoutlet region or outlet panel 132 includes a plurality of apertures 156each preferably corresponding to an associated one of the plurality ofoutlet connectors 160 (FIG. 3A), although it is understood that eachaperture 156 could accommodate more than one outlet connector 160, ifdesired. In some embodiments, the plurality of outlet connectors 160(FIG. 3A) comprises 42 outlet connectors extending substantially theentire length of the housing 130. In other various embodiments, theplurality of outlet connectors 160 (FIG. 3A) can comprise 45, 48, 51, or54 outlet connectors, for example, or any other suitable number.

The power metrics display 152 may be used to provide a local display ofinformation related to the current operating parameters of the PDU 110,such as power-related parameters of the power input cord and/or one ormore of the outlet connectors 160. In one embodiment, the power-relatedparameter is the quantity of current (e.g., amperes) being providedthrough the power input cord and/or one or more of the outlet connectors160. The power-related parameter may also include a quantity of voltage(e.g., volts) being provided through the power input cord and/or one ormore of the outlet connectors 160, a frequency of power (e.g., Hertz)being provided through the power input cord and/or one or more of theoutlet connectors 160, a quantity of power (e.g., Watts) being providedthrough the power input cord and/or one or more of the outlet connectors160, a quantity of power over a period of time, i.e., energy (e.g.,kilowatt hours) being provided through the power input cord and/or oneor more of the outlet connectors 160, and/or other power-relatedparameters. The power metrics display 152 may display one or more of thepower-related parameters using various display technologies, such assegment displays, light-emitting diode displays, and/or liquid crystaldisplays, to name a few. In some embodiments, other operating parametersof the PDU can be monitored and/or displayed, such as configurationdata, IP address, environmental sensor data, residual current, etc.

The communications interface 154 may be coupleable with one or more of alocal computer, local computer network, and/or remote computer network.The communications interface 154 may be used to report informationrelated to current operating parameters of the PDU 110 to one or more ofthe local computer, local computer network, and/or remote computernetwork. The communications interface 154 may also receive informationor instructions related to the operation of the PDU 110 from one or moreof the local computer, local computer network, and/or remote computernetwork. The communications interface 154 may be in communication with acommunications bus of the PDU 110.

In some embodiments, the outlet and non-outlet regions are contained ina common PDU housing, such as housing 130 shown in FIG. 4A. However, inother embodiments, an alternative construction positions the outletregion and the non-outlet region in separate chassis. For example, asshown in FIG. 4B, a PDU 310 can include a vertical chassis 312containing the outlet region and a horizontal chassis 314 containing thenon-outlet region interconnected with one or more cables 316.Accordingly, the horizontal chassis 314 can include the power supplies,circuit protection devices, input power measurement circuits, switchingcircuits, outlet power measurement circuits, environmental sensors,displays, and a network interface module. This allows all of thetemperature sensitive components to be cooled via air from a facility'scold-aisle, which flows through the horizontal chassis 314 and exhaustsout the rear into the facility's hot-aisle. The vertical chassis 312houses the outlets which can operate reliably in the relatively hightemperatures of the facility's hot aisle. By locating the temperaturesensitive components in the cooler horizontal chassis 314, thereliability of those components is greatly enhanced. Therefore, theoverall reliability of the PDU 310 can be enhanced. Furthermore, if acomponent located in the horizontal chassis 314 fails necessitating areplacement of the chassis, the horizontal chassis 314 is much easier toreplace than a PDU containing the outlet and non-outlet regions in onechassis. Returning briefly to FIG. 1D for example, if the inner PDU15(1) fails, essentially all of the cables 17 may need to bedisconnected from both the inner 15(1) and outer 15(2) PDUs in order toremove the inner PDU 15(1) from the equipment cabinet 13. Disconnectingthese power cables may render electronic equipment within the equipmentrack inoperative which is undesirable in a data center environment.Earlier PDU designs exist where the size of the vertical portion of thePDU was reduced by moving displays and a network interface card to ahorizontal enclosure. However, these earlier designs were focused onspace constraints and did not move heat sensitive components out of thevertical enclosure.

As shown in FIG. 5, the plurality of outlet connectors 160 are spacedequidistantly along the length of the PDU 110 and each have a commonconstruction. As described more fully below with respect to FIGS. 10 and11, each outlet connector 160 can include at least three alignedelectrical terminals. It should be appreciated here, however, that theelectrical terminals of each outlet connector 160 are aligned along thelength of the PDU 110. With further reference to FIG. 6, in someembodiments, the outlet connectors 160 are spaced along a pitch P of 1 Uor approximately 1.7 inches.

In some embodiments, the PDU 110 has a width W of between about 1.7inches and about 3.0 inches. In at least one embodiment the PDU 110 hasa width W of approximately 2.18 inches or less. In some embodiments, theoutlet panel 132 has a width W_(O) of approximately 0.83 inches or less.In some embodiments, the outlet panel 132 has a width W_(O) that is lessthan a width of an IEC C14 connector. With reference to FIG. 7, theoutlet panel 132 and the non-outlet panel 134 are offset a distancecorresponding to the height H_(i) of the intermediate panel 135. In someembodiments, the intermediate panel 135 has a height H_(i) of betweenabout 0.4 and about 0.8 inches. In some embodiments, the intermediatepanel 135 has a height H_(i) of approximately 0.5 inches.

Prior art PDUs having 1 U outlet spacing, such as that shown in FIG. 1D,are typically approximately 3.25 inches wide, which requires a deeperrack to accommodate two PDUs side by side. As described above, thedisclosed PDU 110 has a width of approximately 2.18 inches which allowstwo PDUs to be placed side by side in a relatively shallow rack. Inaddition, the narrow width of PDU 110 allows the industry standardkeyhole spacing (i.e., 2.2 inches) to be used to mount the PDUs in thecabinet.

FIG. 8 is an end view in cross-section of the PDU 110 with the end cap144 (FIG. 4.) removed to better illustrate the PDU's construction. Insome embodiments, one or more substrates, such as printed circuit board(PCB) 162, can be mounted within the housing 130 and electricallyconnected to the power input. The outlet connectors 160 are arrangedalong and underneath the outlet panel 132 and mounted to the one or morePCBs 162 with an unobstructed space between adjacent pairs of theplurality of outlet connectors 160. The outlet connectors 160 eachextend a portion of the distance between the one or more PCBs 162 andthe outlet panel 132. Accordingly, the tops of the outlet connectors 160are spaced below the outlet panel 132 a distance D. In some embodiments,the tops of the outlet connectors 160 are spaced below the outlet panel132 a distance D of approximately 1.0 inch. The PCB 162 may includeother electrical circuit components of the PDU 110, such as theovercurrent protection devices 150 (FIG. 4). In some embodiments, thePCB 162 is a multi-layer PCB. Different layers of the multi-layer PCBmay be associated with different phase power lines of the power inputcord (not shown), as further described in U.S. Pat. No. 8,587,950, thedisclosure of which is hereby incorporated by reference in its entirety.Suitable polyphase power input configurations, including wye and deltaconfigurations, are also described in U.S. Pat. No. 9,190,842, thedisclosure of which is hereby incorporated by reference in its entirety.

In some embodiments, the outlet panel 132 can include indicia (e.g.,coloring and/or markings) indicating the phase of the adjacent outletconnector 160. For example, as shown in FIG. 9, the outlet panel 132 caninclude different color coded regions 164, 166, and 168 (indicated withcross-hatching) corresponding to different phases. The color codedregions 164, 166, and 168 can facilitate balancing the load from theelectrical equipment between the different phases. Furthermore, havingthe different phases available along the length of the PDU allows thepower cables to extend straight across between the equipment and the PDUas explained above with respect to FIGS. 2A and 2B.

As shown in FIG. 10, the outlet connector 160 is a non-industry standardconnector, e.g., it is not an IEC or NEMA standard connector. In someembodiments, the outlet connector 160 includes an outlet core 170 and anend cap 172 connected to the outlet core. In some embodiments, the endcap 172 (e.g., the face of the connector) can be colored or marked toreflect its connection to polyphaser input. With further reference toFIG. 11, outlet connector 160 includes a plurality of electricalterminals 174 and 176. Electrical terminals 174 and 176 are positionedbetween the outlet core 170 and the end cap 172. Connector 160 includestwo outer electrical terminals 174 and a middle electrical terminal 176.In some embodiments, electrical terminals 174 and 176 have the sameconstruction although middle terminal 176 is positioned to face theopposite direction of electrical terminals 174. Thus, although theelectrical terminals are aligned with respect to each other, the middleconnection tab is offset from the outer electrical terminal's connectiontabs. In other embodiments, the terminals may be different sizes. Forexample, in this embodiment middle terminal 176 is larger than the outerterminals 174.

In some embodiments, electrical terminals 174 and 176 are constructedfrom suitable electrically conductive materials such as tin, gold,silver, copper, phosphor bronze, and the like. Multiple materials can beused in combination. In one embodiment, the terminals comprise copperalloy with a tin plating. In some embodiments, the terminals such asouter terminals 174 are formed from a single piece of conductivematerial by bending contacts 180 and 182 away from connection tab 178.Although the electrical terminals are aligned with respect to eachother, the middle connection tab is offset from the outer electricalterminals' connection tabs. Contacts 180 and 182 are bent inward towardseach other such that when a mating contact (not shown) is inserted intothe electrical terminal, the contacts 180 and 182 are urged toward themating terminal. Accordingly, in some embodiments it is desirable toform the electrical terminals 174 and 176 from a conductive resilientspring-like material. Connection tabs 178 extend through and beyond theinput side 184 of the connector core 170. Likewise, contacts 180 and 182are positioned toward the output side 186 of the outlet core 170. It canbe appreciated from the figure that electrical terminals 174 and 176 areconfigured as female receptacles. In other embodiments the electricalterminals 174 and 176 may be configured as male terminals or acombination of male and female terminals.

As shown in FIG. 11, end cap 172 is insertable into cavity 188 formed inoutlet core 170. Internal indexing features 190 and 192 help ensure thatend cap 172 is inserted into cavity 188 in the correct orientation.Features 190 and 192 act in cooperation with indexing relief feature 194formed into the side of cavity 188. In some embodiments, the outletconnector 160 is mountable to a printed circuit board or other surfacewith mounting screws 196. The outlet connector 160 is further describedin co-pending U.S. patent application Ser. No. 14/687,670, filed Apr.15, 2015, the disclosure of which is hereby incorporated by reference inits entirety.

As mentioned above, the power connector adapter 116, as shown in FIG.12, is configured to adapt an IEC C13/C14 power cord to an outletconnector 160 (FIG. 9). In a representative embodiment, the powerconnector adapter 116 can include a first connector 200 configured tomate with an industry standard connector. For example, in the depictedembodiment, the first connector 200 is configured as an IEC C13 in orderto mate with a C14 connector of a standard power cord (not shown). Thepower connector adapter 116 also includes a second connector 202 (alsoreferred to herein as a PDU connector) configured to mate with outletconnector 160. A first attachment mechanism 204 is associated with thefirst connector 200 and a second attachment mechanism 206 is associatedwith the second connector 202.

FIG. 13 illustrates another power connector adapter 118 similar to powerconnector adapter 116 except that power connector adapter 118 isconfigured to adapt an IEC C19/C20 power cord to an outlet connector160. The power connector adapter 118 can include a first connector 210configured as an IEC C19 in order to mate with a C20 connector of astandard power cord (not shown). The power connector adapter 118 alsoincludes a second connector 212 configured to mate with outlet connector160. A first attachment mechanism 214 is associated with the firstconnector 210 and a second attachment mechanism 216 is associated withthe second connector 212.

With reference to FIG. 14, the second connector 212 includes a shroudportion 220 configured to mate with the outlet core 170 (FIG. 10) of theoutlet connector 160. Male terminals 222 are positioned in the shroud220 to mate with corresponding terminals 174 and 176 of the outletconnector 160 (FIG. 11). In some embodiments, the second attachmentmechanism 216 can include a spring arm 224 integrally formed with ahousing 223 of the power connector adapter 118. A latch barb 228 isdisposed on the spring arm 224 at an approximate midpoint thereof. Thespring arm 224 extends from a first end portion connected to the housing223 to terminate at a second end portion having an actuation button 226.When the second connector 212 is inserted into an aperture 156 (FIG. 8)to mate with an outlet connector 160, the latch barb 228 engages, in asecured state, a portion (e.g., a lip) of the outlet panel 132 therebyretainably coupling the power connector adapter 118 to the PDU 110. Whena user pushes the actuation button 226, the latch barb 228 is moved fromthe secured state to an unsecured state thereby allowing removal of thepower connector adapter 118 from the PDU 110. It should be readilyunderstood that the second connector 202 and the second attachmentmechanism 206 of power adapter 116 (FIG. 12) can each be constructed ina substantially similar manner to that described here with respect toFIG. 14.

It can be appreciated in at least FIGS. 12-14 that the second connectors202 and 212 are noticeably smaller than the industry standard C14 andC20 connectors, 201 and 211 respectively, that mate with the firstconnectors 200 and 210. Furthermore, the mating PDU connectors or outletconnectors 160 are smaller still. The relatively small size of theoutlet connectors 160 allows them to be spaced at 1 U. In addition, therelatively small size of the outlet connectors 160, in conjunction withthe orientation of the overcurrent protection devices 150, allow the PDU110 to have a narrower width than is possible with industry standardconnectors.

FIG. 15 is an isometric view of the power connector adapter 116 with onehalf of the housing 225 removed to illustrate the internal components ofthe connector adapter. Male terminals 221 are connected to correspondingfemale terminals 230 via conductors 234. In some embodiments, theconductors 234 are crimped and/or soldered to the male and femaleterminals 221 and 230, respectively. The first attachment mechanism 204includes a latch assembly 232 with a releasable latch plate 233configured to engage a male pin of a mating C14 connector, for example.

As shown in FIG. 16, the housing 225 can include a latch cover 236mounted on an interior surface of the housing 225 behind the secondattachment mechanism 206 (FIG. 12). The latch cover 236 covers the gaparound the second attachment mechanism 206 ensuring that the internalcomponents (e.g., conductors 234 and terminals 221 and 230) are securelyenclosed to prevent a user from contacting them. The latch cover 236includes a pocket 240 that allows the attachment mechanism to bedepressed by a user. In some embodiments, the latch cover 236 ispositioned on pins 238 extending from the housing 225. Once the latchcover 236 is in position, the pins 238 can be melted to heat stake thecover 236 in place.

FIG. 17A is an isometric view of the smart cable 120 introduced above.The smart cable 120 is configured to connect electrical equipment to thedisclosed PDUs 110. In some embodiments, the smart cable 120 isconfigured to report power-related information about the electricalequipment, switch power on and off to the electrical equipment and/orreport a unique identifier corresponding to the equipment to the PDU.

In a representative embodiment, the smart cable 120 includes a connector124 configured to removably connect the smart cable 120 to a mateableinterface of the PDU 110 (e.g., outlet connector 160). Accordingly,various features of the connector 124 can be constructed similarly,where suitable, to corresponding features of power connector adapters116 and 118 described above. A power output cable 250 extends into theconnector housing 252 at one end and couples to an output connector 254at the opposite end. The output connector 254 is schematicallyillustrated to generically represent various connectors, such as IEC andNEMA connector configurations. In at least one embodiment, the outputconnector 254 can be configured as an IEC C13 connector. In someembodiments, the smart cable 120 includes a unique identifier encoded(e.g., pre-programmed) in an internal memory device that can be used totrack the cable and/or electronic equipment connected to the smart cable120. In some embodiments, the smart cable includes indicia 256corresponding to the unique identifier. In the depicted embodiment, theindicia is disposed on a tag 258 that can be attached to the poweroutput cable 250, for example. In some embodiments, an additional tag257 (e.g., sticker) including duplicate indicia 256 can be attached tothe electronic equipment being tracked or to the smart cable 120 in aposition that can be easily viewed for tracking. In some embodiments,tag 258 can be attached to the electronic equipment, thereby helpingensure that the cable remains with the equipment for tracking purposes.In some embodiments, the smart cable can include LEDs indicating On/Offstatus. In some embodiments, LEDs can indicate a power parameter levelbased upon programmable or preset thresholds each corresponding to adifferent color on a multicolor LED or by flashing.

In another representative embodiment shown in FIG. 17B, a smart cable260 can include a connector 267 (e.g., receptacle) configured to receivea mating connector 268 of an identifier tag 264. Rather than having apre-programmed identifier, the smart cable 260 reads a unique identifierfrom the tag 264 when it is connected. In some embodiments, the uniqueidentifier can be stored on a memory device 266, such as a microchip,RFID tag, or other readable device and/or media. In some embodiments,the identifier tag 264 includes indicia 262 corresponding to the uniqueidentifier stored in memory device 266. In some embodiments, anadditional tag 265 (e.g., sticker) including duplicate indicia 262 canbe attached to the electronic equipment being tracked or to the smartcable 260 in a position that can be easily viewed for tracking. In someembodiments, tag 264 can be attached to the electronic equipment,thereby helping ensure that the tag remains with the equipment fortracking purposes.

Once an identifier tag (e.g., tag 258 or tag 264) is physically attachedto the electronic equipment, information about that equipment can beassociated with the tag's unique identifier in a database. For example,a description and a location of the equipment can be entered into thedatabase corresponding to the tag's unique identifier. Accordingly, wheninformation, such as power-related information or parameters, isreported from a smart cable via the network interface card, thatinformation is reported along with the tag's unique identifier so thatthe information can be associated with the equipment. If the electronicequipment is subsequently moved, the database can be updated with theequipment's new location with the same unique identifier. If theequipment is replaced, a new tag can be placed on the equipment and thetag's unique identifier can be entered into the database with the newequipment's description and location.

As shown in FIG. 18, the smart cable 120 contains a PDU interface 280disposed in the connector housing 252. In some embodiments, the PDUinterface comprises a PCB with various circuitry. For example, the PDUinterface 280 can include a sensing device configured to sense at leastone power-related parameter of the power output cable 250 and an opticalsignal interface 282. In addition, the PDU interface 280 can include amemory device for storing a preprogramed unique identifier and/orcircuitry to read a unique identifier from an identifier tag 264 (FIG.17B). The optical signal interface 282 is configured to report thepower-related parameter and the unique identifier to the PDU 110 whichcan include a suitable interface to communicate with the PDU interface280. The optical interface provides at least two main advantages. Itprovides a non-contact interface between the PDU and the smart cableeliminating the need for a connector on the smart cable and a matingconnector on the PDU. It also provides electrical isolation so that thepower supply in the smart cable can be derived (and referenced) directlyfrom the AC source which allows for a smaller circuit as isolationbetween the low voltage DC and high voltage AC is not required. Theoptical interface isolates the user of the PDU from the high voltage AC,used to power the circuitry contained within the smart cable, inaccordance with applicable safety agency standards.

In some embodiments, the smart cable 120 can receive control signalsfrom the PDU, via the optical signal interface, to control the operationof the smart cable. For example, the control signals may control theoperation of a relay within the smart cable 120. The control signals mayswitch the relay between a first state which allows current to flowthrough the power output cord 250 of the smart cable 120, and a secondstate which prevents current from flowing through the power output cord250. In some embodiments, a smart cable can include all of the necessarycircuitry to provide all of the features described herein (i.e.switching, metering, asset tracking, etc.) with the ability to turnvarious features on and off via purchasable keys (e.g., software key) soa customer can upgrade to additional functionality in the future withouthaving to change cables. This also allows the manufacturer to build andstock a single smart cord that can support all of the neededfunctionality but can be configured to provide only the requestedfunctionality at the time an order is placed thus reducing inventorycosts.

FIGS. 19-22 illustrate various circuits contained in the PDU interface280 of the smart cable 120. FIG. 19 is a schematic diagram illustratinga power supply circuit 1900 according to a representative embodiment.The power supply circuit 1900 derives low voltage from the AC input linethat is used to power the smart cable. The power supply circuit 1900includes an offline power supply circuit 1902 and an on-sense/frequencydetection circuit 1904. The offline power supply circuit 1902 isoperative to convert line voltage (e.g., 75-260 VAC) to 5 VDC forpowering the various microprocessors and electronics of the PDUinterface 280.

In the depicted embodiment, the offline power supply circuit 1902includes a half-wave rectifier 1906, comprising R1 and D1, which chargesa capacitor C1 to the peak of the line voltage (e.g., 75-260 VAC). U1connects capacitor C1 to inductor L1 very briefly, thereby charginginductor L1 to approximately 0.3 Amps. When the magnetic field of theinductor L1 collapses, the energy in the inductor flows into an outputfilter capacitor C3, and a feedback circuit 1908, comprising R2 and D4,provides a 3.9 V signal to the optical isolator U2. The optical isolatorU2 provides a feedback signal (FB) to the IC U1 signaling it to stopcharging L1. This charging cycle happens approximately 67,000times/second.

The on-sense/frequency detection circuit 1904 provides a signal(ONS/freq) indicating when the power line voltage is zero to allow relayswitching at low line voltage to preserve the relay contacts. Theon-sense/frequency detection circuit 1904 includes a voltage divider1910 to reduce the line voltage to less than 3 Volts. A low pass filterC6 stops high frequency noise from disrupting other components in thecircuitry, such as an analog to digital (A/D) convertor. A voltagebiasing circuit 1912, comprising C5, R10, and R12, provides 1.65 voltsto an A/D convertor on the microprocessor 2152 (FIG. 21B). Voltage onsignal VS varies around this bias voltage according to the line voltageinput. An operational amplifier U3:1 provides a square wave outputranging from 0 to 3.3 volts according to whether the line voltage isnegative or positive, respectively. Thus, the square wave output fromU3:1 provides accurate zero crossing information about the wave form ofthe line voltage input. Thus, the square wave can be used to time whento energize the coils in the relays that provide power to the outletssuch that the contacts close when the line voltage is at the zerocrossing point of the waveform.

FIG. 20 is a schematic diagram illustrating an infrared (IR)communication circuit 2000 according to a representative embodiment. TheIR communication circuit 2000 includes a two volt reference (2 VR)circuit 2002, a transceiver circuit 2004, and a noise control circuit2006. The transceiver circuit 2004 includes an IR light emitting diode(LED) identified in the circuit as LED1. The transceiver circuit 2004 isoperative to both transmit and receive data optically to and from thePDU using LED1. The optical signal interface 282 (FIG. 18) can include alight pipe to transfer light between the LED1 and an optical interface2300 of the PDU, as described below with respect to FIG. 23. An inverterU16 inverts a TXD signal from the microprocessor 2152 (FIG. 21B) whichin turn activates the transistor Q1 to turn the LED1 on and off in orderto transmit a signal when in a transmit mode. In some embodiments, theIR communication circuit 2000 can include a transmit gate U17 thatallows the microprocessor to shut off output from comparator U18:4 whenthe circuit is in the transmit mode in order to prevent erroneous signaldata from appearing on the RXD input. When the IR communication circuit2000 is in a receive mode, light coming into the LED1 produces a smallcurrent which produces a high signal from operational amplifier U18:2. Apeak detector circuit 2008, including operational amplifier U18:3,provides a reference signal, which is half way between the maximum andminimum value of the receive signal, to comparator U18:4 which providesthe received waveform (RXD) to the microprocessor with no biasdistortion. The 2 VR circuit 2002 sets the voltage across the LED1 whenthe transceiver circuit 2004 is receiving data.

FIG. 21A is a circuit diagram illustrating an example of a currentsensing circuit 2100 and a latching relay circuit 2120 of the smartcable 120, in accordance with a representative embodiment. The currentsensing circuit 2100 includes a magneto-resistive sensor device 2102 forsensing the current flowing through a power output cord of a smartcable. In some embodiments, the magneto-resistive sensor device 2102 maybe a magnetic tunnel junction (MTJ) sensor device, such as device partnumber CTSR218 manufactured by Crocus Technology. In some embodiments,the magneto-resistive sensor device 2102 may be encircled by ferriteshielding to mitigate interfering magnetic fields generated by nearbyelectronic or magnetic devices.

The magneto-resistive sensor device 2102 is configured to determineand/or otherwise measure the strength of a proximate alternatingmagnetic field that is associated with a power output cord of each smartcable. Based on the measured magnetic field, the current sensing circuit2100 outputs a “current-sense” signal 2104 indicative of the currentflowing through the power output cord of the smart cable. In someembodiments, the current sensing circuit 2100 may use other circuitconfigurations, such as those described in U.S. application Ser. No.14/959,207, entitled “Magneto-Resistive Sensor Device and Magnetic BiasRegulator Circuit, Along With Systems And Methods Incorporating Same,”filed on Dec. 4, 2015, which is incorporated by reference herein in itsentirety.

The relay circuit 2120 includes a relay 2122 which controls the flow ofcurrent through a power output cord of a smart cable. The relay 2122 maybe a basic electromagnetic relay, a latching relay, or other type ofelectronic switching device. The relay 2122 switches between a firststate which allows current to flow through the power output cord, and asecond state which prevents current from flowing through the poweroutput cord. The state of the relay 2122 is controlled by a drivercircuit 2124. The driver circuit 2124 receives a relay control signal2126 from the microprocessor 2152. In response to the relay controlsignal 2126, the driver circuit 2124 provides one or more signals whichcontrol the state of the relay 2122.

With further reference to FIG. 21B and the microprocessor circuit 2150,the current sensing circuit 2100 provides current information (e.g.,current-sense signal 2104) to the microprocessor 2152 and themicroprocessor 2152 provides control signals (e.g., relay control signal2126) to the latching relay circuit 2120. Accordingly, themicroprocessor 2152 can control switching of line voltage to the outputconnector via the latching relay circuit 2120. FIG. 22 is a schematicdiagram illustrating an example of a linear regulator circuit 2200,including a fixed-output voltage regulator 2202, operative to convert 5volts to 3.3 volts to run the microprocessor 2152 (FIG. 21B).

FIG. 23 is a circuit diagram illustrating an example of a smart cablecommunication interface 2300 of the PDU 110, in accordance with variousaspects of the present disclosure. The smart cable communicationinterface 2300 includes a display controller 2302 associated with thepower metrics display 152 (FIG. 4A), a power input monitoring controller2304, and a plurality of optical communication interface hubs 2306, allof which are connected to a network interface card (NIC) 2308. Eachoptical interface hub 2306 is operative to communicate with a pluralityof smart cables 120 via each smart cable's optical interface circuit2000, depicted as an IR interface (FIG. 20). Accordingly, thepower-related parameters and unique identifier information associatedwith each smart cable 120 can be communicated to the PDU, which in turncan communicate that information to a network via the NIC 2308 and thecommunications interface 154 (FIG. 4). Each optical interface hub 2306includes an aggregator 2310 comprised of a microcontroller operative topoll each of a plurality of transceivers 2312. The aggregator 2310transmits information and commands to one cable at a time by activatinga corresponding transmit enable output (e.g., TXEN1). Since only onecable will be responding, at a time, all of the receive circuits can beor'ed together. The output of the or'ed receive signals can be gated bythe microprocessor, via the control signal (RXEN), so that themicroprocessor is only allowed to monitor receive data when receive datais expected. This arrangement for the receive circuits simplifies thecircuitry and reduces power consumption.

Each transceiver 2312 includes an IR LED 2314 positioned adjacent acorresponding outlet connector 160 such that when a smart cord 120 isconnected to the outlet connector 160, the transceiver 2312 cancommunicate with the smart cord's PDU interface 280 (FIG. 18). In someembodiments, the transceivers 2312 can comprise circuitry similar to theIR communication circuit 2000 described above with respect to FIG. 20.Although the depicted embodiment comprises three optical interface hubs2306 each having ten transceiver circuits 2312, other embodiments canhave more or fewer optical interface hubs 2306 and/or transceivercircuits 2312.

It should be understood that various combinations of and modificationsto the various disclosed embodiments are possible. For example, in someembodiments the power connector adaptors 116 and 118 could include a PDUinterface 280, thereby making a smart adapter. Furthermore, the firstand second connectors of the power connector adapters 116 and 118 couldbe separate connectors interconnected with a suitable power cord. Theseand other permutations and combinations are described below with respectto FIGS. 24A-25H, for example and without limitation.

FIG. 24A schematically represents the power connector adapter 116described above with respect to FIG. 12. As shown, the power connectoradapter 116 comprises a unitary body having a C13 connector at one endand a PDU connector mateable with an outlet connector 160 at the otherend. FIG. 24B schematically represents the power connector adapter 118described above with respect to FIG. 13. As shown, the power connectoradapter 118 comprises a unitary body having a C19 connector at one endand a PDU connector at the other end. FIG. 24C schematically representsa power connector adapter 290 including a cable interconnecting a C13connector and a PDU connector. The C13 and PDU connectors can be similarto those described herein. In some embodiments, the cable is a short,“pig-tail” cable, and in other various embodiments the cable can be oneof many selected lengths. FIG. 24D schematically represents a powerconnector adapter 292 that is similar to power connector adapter 290including a C19 connector instead of the C13 connector. In someembodiments, the power connector adapters 116 and 118 can comprise twoor more mateable pieces or can be comprised of a single unitaryconstruction.

FIG. 25A schematically represents a smart power connector adapter 294comprising a unitary body having a C13 connector at one end and a PDUconnector mateable with an outlet connector 160 at the other end. Thepower connector adapter 294 also includes a PDU interface (SMART), suchas PDU interface 280 (FIG. 18). FIG. 25B schematically represents asmart power connector adapter 296 that is similar to power connectoradapter 294 including a C19 connector instead of the C13 connector. Insome embodiments, the power connector adapters 294 and 296 can comprisetwo or more mateable pieces or can be comprised of a single unitaryconstruction. FIG. 25C schematically represents the smart cable 120described above with respect to FIGS. 3A and 17A. The smart cable 120comprises a cable interconnecting a C13 connector and a PDU connector.The PDU connector includes the PDU interface (SMART) shown in FIG. 18.FIG. 25D schematically represents a smart cable 298 that is similar tosmart cable 120 including a C19 connector instead of the C13 connector.FIG. 25E schematically represents the smart cable 122 described abovewith respect to FIG. 3B. The smart cable 122 is similar to smart cable120 and includes a cable interconnecting a C13 connector and a PDUconnector. However, the C13 connector includes the PDU interface (SMART)instead of the PDU connector. FIG. 25F schematically represents a smartcable 300 that is similar to smart cable 122 including a C19 connectorinstead of the C13 connector. FIG. 25G schematically represents a smartcable 302 comprising a cable interconnecting a C13 connector and a PDUconnector. The smart cable 302 includes a housing 304 positioned betweenthe C13 and PDU connectors and containing the PDU interface (SMART).FIG. 25H schematically represents a smart cable 306 that is similar tosmart cable 302 including a C19 connector instead of the C13 connector.

In some embodiments, the smart cables 122 and 300 can include wired oroptical communication cables extending from the C13 and C19 connectorsalong the cable to the PDU end of the cable for interfacing with thePDU's optical interface hub 2306 (FIG. 23). In some embodiments, thesmart power connector adapters depicted in FIGS. 25A-25H can includewireless communication between the smart cable and the PDU.

FIGS. 26-29 illustrate a cable identification system 400 according to arepresentative embodiment. In some applications it is desirable toidentify if and what type of cable 402 (e.g., C13, C19, and/or smartcable) is plugged into a PDU, such as PDU section 420. This informationcan be used to determine if a cable is present, if a piece of equipmentis exceeding current limits for a particular cable and/or outlet, or ifa smart cable has failed or lost power, for example. With reference toFIG. 26, cable 402 is a basic adapter cable (i.e., non-intelligent)having a PDU connector 408, a standard connector 406 (e.g., C13), and acable 404 extending therebetween. The PDU section 420 is similar to aportion of PDU 110 described above and includes a buss board PCB 422 anda communication PCB 424 both contained in housing 426. The buss boardPCB 422 supports a plurality of outlet connectors 160 that mate with PDUconnector 408.

As shown in FIG. 27, the PDU connector 408 can include first and secondmagnets 410 and 412, respectively. The presence or absence of thesemagnets can be used to determine the type of cable connected to the PDU.For example, the connector 408 can include only the first magnet 410,only the second magnet 412, both the first and second magnets 410 and412, or no magnets to indicate that the cable is a C13, a C19, a smartcable, or that no cable is present, respectively. In the case of a smartcable, the PDU connector can also include an IR LED 414 to communicatewith the PDU as explained above with respect to FIG. 23. In someembodiments, the magnets 410 and 412 can be cylindrical magnetscomprising a suitable magnetic material such as neodymium, for example.

With further reference to FIGS. 28 and 29, the communication PCB 424includes hall effect sensors, such as sensors 450 and 452 to detectwhich if any magnets are present, by sensing the magnetic fieldgenerated by either or both of the installed magnets, in a connector408. Thus, the presence of and what type of cable can be determinedbased on which of the two hall effect sensors 450 and 452 detect amagnet. It should be appreciated that different numbers and positions ofmagnets can be located on the connector 408 in order to encodeinformation pertaining to the cable.

In some embodiments, flux from the magnets, such as magnet 412, can betransferred to the corresponding hall effect sensor 452 through one ofthe outlet connector's mounting screws 196 (see also FIG. 11), whichscrew is used to mount the connector 160 to the buss board 422. In someembodiments, the flux transferred through screw 196 can be concentratedat the sensor 452 with a metal flux concentrator 454 positioned on thecommunication PCB 424 opposite the sensor 452. The flux concentrator 454can significantly enhance the flux to the sensor, up to at least 35% insome cases. Directing the flux from magnet 412 with screw 196 and fluxconcentrator 454 allows the magnet to be relatively far away from thehall effect sensor 452 and still operate reliably.

Embodiments described herein provide several benefits relative totraditional PDUs. For example, various combinations of the PDU,adapters, and smart adapters disclosed herein allow users to configureoutlets as C13 or C19, for example, on a per outlet and on an as neededbasis. Also, switching, tracking, and power monitoring capabilities canbe provided on an as needed per outlet basis using the disclosed smartcables and adapters. The 1 U spacing of outlets provided in a 2.2 inchwide chassis allows two PDUs to be mounted side-by-side in a rack suchthat two outlets are directly across from each rack unit. Thisarrangement simplifies cable management and lends itself to a userfriendly, intuitive asset tracking solution. It will be noted that thislist of various advantages is not exhaustive or exclusive, and numerousdifferent advantages and efficiencies may be achieved, as will berecognized by one of skill in the art.

It should be noted that the systems, methods, and devices discussedabove are intended merely to be examples. Other examples of smart cablescan include a smart cable for removable attachment to a powerdistribution unit (PDU), comprising: a connector housing configured toremovably connect the smart cable to a mateable interface of a PDU; apower output cable having a proximal end extending into the connectorhousing and a distal end coupled with an output connector that isconfigured to connect to electronic equipment; a PDU interfaceassociated with the connector housing, the PDU interface including: aunique identifier encoded in a memory device; at least one sensingdevice configured to sense at least one power-related parameter of thepower output cable; and at least one optical signal interface configuredto report the at least one power-related parameter and the uniqueidentifier to the PDU; and indicia corresponding to the uniqueidentifier attached to the power output cable.

Other examples of power connector adapters can include a power connectoradapter, comprising: a first connector configured to mate with anindustry standard connector; a second connector configured to mate witha non-industry standard connector and including at least three alignedterminals; a plurality of conductors extending between the firstconnector and the second connector; a first attachment mechanismassociated with the first connector; and a second attachment mechanismassociated with the second connector and movable from a secured state,in which said attachment mechanism can retainably couple the powerconnector adapter to a PDU, to an unsecured state to allow removal ofthe power connector adapter from the PDU.

It must be stressed that various embodiments may omit, substitute, oradd various procedures or components as appropriate. For instance, itshould be appreciated that, in alternative embodiments, featuresdescribed with respect to certain embodiments may be combined in variousother embodiments. Different aspects and elements of the embodiments maybe combined in a similar manner. Also, it should be emphasized thattechnology evolves and, thus, many of the elements are exemplary innature and should not be interpreted to limit the scope of theinvention.

Specific details are given in the description to provide a thoroughunderstanding of the embodiments. However, it will be understood by oneof ordinary skill in the art that the embodiments may be practicedwithout these specific details. For example, well-known circuits,structures, and techniques have been shown without unnecessary detail inorder to avoid obscuring the embodiments.

Having described several embodiments, it will be recognized by those ofskill in the art that various modifications, alternative constructions,and equivalents may be used without departing from the spirit of theinvention. For example, the above elements may merely be a component ofa larger system, wherein other rules may take precedence over orotherwise modify the application of the invention. Also, a number ofsteps may be undertaken before, during, or after the above elements areconsidered. Accordingly, the above description should not be taken aslimiting the scope of the invention.

We claim:
 1. An adapter for interconnecting a power distribution unit(PDU) to electrical equipment, comprising: a first connector mateablewith an outlet of the PDU; a second connector in electricalcommunication with said first connector, said second connector mateablewith a power input of the electrical equipment; and PDU interfacecircuitry incorporating an optically isolated digital interface housedin the first connector for communicating one or more electricalparameters of the electrical equipment to the PDU when the firstconnector is mated with the outlet of the PDU.
 2. An adapter accordingto claim 1 wherein said PDU interface circuitry comprises: memorystoring a unique identifier associated with the electrical equipment; atag having indicia corresponding to a unique identifier associated withthe electrical equipment, and interrogation circuitry for reading saidunique identifier.
 3. An adapter according to claim 1 wherein saidsecond connector comprises an electrical equipment connector housing,and wherein at least a portion of said PDU interface circuitry isdisposed within said electrical equipment connector housing.
 4. Anadapter according to claim 1 wherein at least a portion of said PDUinterface circuitry is in a housing that is positioned between saidfirst connector and said second connector.
 5. An adapter according toclaim 1 further comprising a communication cable interconnecting saidfirst connector to said second connector.
 6. An adapter according toclaim 5 wherein said communication cable is a wired cable.
 7. An adapteraccording to claim 5 wherein said communication cable is an opticalcable.
 8. An adapter according to claim 1 wherein said second connectoris one of an IEC C13 type connector and an IEC C19 type connector.
 9. Anadapter according to claim 1 wherein said first connector comprisesthree aligned terminals.
 10. An adapter according to claim 1 whereinsaid first connector comprises a power connector adapter having a firstend comprising three aligned terminals, and a second end configured tomate with an IEC C14 plug or an IEC C20 plug.
 11. An adapter accordingto claim 10 wherein a portion of said first connector is configured aseither an IEC C14 plug or and an IEC C20 plug which is removablyconnectable to said power connector adapter.
 12. An adapter according toclaim 1, wherein said PDU interface circuitry includes a power supplycircuit to power the PDU interface.
 13. An adapter according to claim12, wherein said power supply circuit includes an offline power supplycircuit that converts an incoming AC voltage to a DC voltage to powerthe PDU interface.
 14. An adapter according to claim 13, wherein saidPDU interface circuitry includes a relay circuit having a first stateand a second state, the relay circuit switching between the first stateand the second state to control a flow of current from the firstconnector to the second connector, the power supply circuit including anon-sense/frequency detection circuit to permit the relay to switch atlow line voltage.
 15. An adapter according to claim 1, wherein said PDUinterface circuitry includes an optical interface circuit that comprisesan infrared (IR) communication circuit having a two volt referencecircuit, a transceiver circuit and a noise control circuit.
 16. Anadapter according to claim 1, wherein said adapter includes a poweroutput cord and the PDU interface circuitry includes a current sensingcircuit and a latching relay circuit, the current sensing circuitincluding a magneto-resistive sensor for sensing current through thepower output cord, the latching relay circuit including a relay tocontrol the flow of current through the output cord.
 17. A powerdistribution system, comprising: a power distribution unit (PDU),comprising: a housing; an input adapted to receive input power from apower source; a plurality of outputs for provisioning power toelectrical equipment; and a network interface; and at least one smartcable interconnecting said PDU to electrical equipment, said at leastone smart cable adapter comprising: a first connector mated with atleast one of said outputs; a second connector in electricalcommunication with said first connector via a power output cable, saidsecond connector mateable with a power input of the electricalequipment; and at least one PDU interface circuit comprising anoptically isolated digital interface housed in the first connector forcommunicating power related parameters of the electrical equipment tothe PDU when the first connector is mated with the at least one outputof the PDU.
 18. A power distribution system according to claim 17wherein at least one of said outputs of the PDU comprises three alignedapertures, and wherein said first connector is configured to mate withsaid three aligned apertures.
 19. A power distribution system accordingto claim 18 wherein the first connector of said smart cable adaptercomprises a power connector adapter having a first end comprising threealigned apertures.
 20. A power distribution system according to claim 17wherein said PDU comprises at least one smart cable interface operativeto communicate with the at least one PDU interface circuit of said atleast one smart cable adapter such that power-related parameters of saidat least one smart cable adapter can be communicated to said PDU, andfrom said PDU, over a network via said network interface.
 21. A powerdistribution system according to claim 20 wherein said least one smartcable interface circuitry includes at least one optical communicationinterface hub interconnected to said network interface.
 22. A powerdistribution system according to claim 20 wherein said smart cableadapter comprises a selected number of magnets to indicate aconfiguration type of said smart cable adapter, and wherein said PDUincludes at least a corresponding number of sensors for detecting apresence or an absence of said selected number of magnets.
 23. Anadapter according to claim 1 wherein said PDU interface circuitryfurther comprises a memory device configured to store a uniqueidentifier associated with the electrical equipment and wherein the PDUinterface circuitry communicates the unique identifier to the PDU.
 24. Apower distribution system according to claim 17 wherein said PDUinterface circuit further comprises a memory device configured to storea unique identifier associated with the electrical equipment and whereinthe PDU interface circuitry communicates the unique identifier to thePDU.
 25. A power distribution system according to claim 17, wherein saidPDU interface circuit includes a power supply circuit to power the PDUinterface circuit.
 26. A power distribution system according to claim25, wherein said power supply circuit includes an offline power supplycircuit that converts an incoming AC voltage to a DC voltage to powerthe PDU interface.
 27. A power distribution system according to claim26, wherein said PDU interface circuit includes a relay circuit having afirst state and a second state, the relay circuit switching between thefirst state and the second state to control the flow of current throughthe power output cable, the power supply circuit including anon-sense/frequency detection circuit to permit the relay to switch atlow line voltage.
 28. A power distribution system according to claim 17,wherein said at least one smart cable adapter includes a plurality ofsmart cable adapters each having an optical interface circuit, the PDUincluding a smart cable communication interface in communication withthe network interface, the smart cable communication interface having adisplay controller, a power metric display associated with the displaycontroller, a power input monitoring controller and a plurality ofoptical communication interface hubs in communication with the pluralityof smart cable adapters via the optical interface circuits.